Cowl fastener



ug. l2, WM. c. E. HATHORN ,252,286

COWL FASTENER Filed Sept. 14, 1939 lll-lill l Illl llllllll INVENTOR CHAQLES E. HATHOQN.

BY' f e f f ATTORNEY Patented ug. 12, 1941 Charles E. HathormKenmore, N. Y., assignor `to Curtiss-Wright Corporation, a corporation oi Delaware Application september 14, i939, serial Ne. 294,817 v e CLM- 221) I e l 2 Claims.

This invention relates to cowl fasteners, the devices of the invention being particularly applicabl to aircraft cowling Vand inspection plates which must be readily removable, but which must be secure when assembled.

A particular object of the invention is to provide a fastener assembly of simple construction which may be readily manufactured at a lowv price which, at the same time, will provide` for easy detachment, and which will provide a flush exterior surface. f

Further objects will be apparent from a reading of the annexed specification and claims, together with an examination of the accompanying drawing, in which:

Fig. 1 shows a pair of plates embodying the invention; f

Fig. 2 is a plan of a plate incorporating the cowl fastener;

\ Figs. 3 and 4 are sections through plates joined by the fastener respectively in the assembly and secured positions;

Fig. 5 is a perspective view of ments of the'fastener;

Fig. 6 is a perspective view of a plate to which is secured another element of the fastener, and

Fig. 7 is a section through a boxl incorporating an alternative embodiment.

A plate I0 is adapted to overlie and be secured to a plate I I, the two plates having aligned holes I3 and I4, the plate adjacent to the hole I3- being countersunk slightly as at I5. A cup element I6 is inserted through the hole I3,/this cup having an outwardly extending flange I1 lying in the depression I5, and having an inwardly projecting flange I8 at its lower or inner end. In the cup, a mandrel I9 is disposed, said mandrel having a screw head 20 adjacent the plane of the plate I0, and a bulbous portion 2l at its lower end, the latter projecting beyond thel cup flange I3. A compression spring 22 is disposed between the head 2|) and the flange I8, urging the bulbous portion 2| toward the plate III. Said bulbous 4portion has opposed cutouts which form barbs 24.

The plate II carries a spring element 26 comprising a base secured to the plate .I I as by rivets 21, said base having a hole aligned with and' of the same size as the hole I4, and having inwardly projecting integral arms 28, the innermost ends of which arms are inturned as at 29 to form elements which engage within the barb notches 24 when the plate I0 is assembled over the plate I I and when the mandrel I 9 is pressed inwardly. Fig. 3 shows the position of the elements when vone of the elethe plate `I0` is first assembled over the plate `I I. Fig. 4 shows, in dottedl lines, the spreading `of the arms 28 by the bulb 2I as the mandrel is pressed inwardly. When the bulb passes beyond the inturned spring arm portions 29, the latter spring inwardly, into the barb recesses, to secure the plates I0 and II from spreading. To unlock the assembly, it is' merely necessary to turn the mandrel I9 by means of a screwdriver, whereby the portions 29 are cammed apart to disengage the barbs 24, whereupon the plate III with its attached parts may be lifted clear of the plate II.

The figures show rubber pads 30 secured to the plate II against which the plate III may rest when in assembled position. The spring 22 serves to resiliently hold the parts in assembled relation, and it will be noted that considerable clearance may be provided in the hole I4 without affecting proper locking of the mechanism so that the plates III and II may be moved around slightly with respect to one another avoiding the necessity of absolutely perfect alignment of the plates when they are placed together.

Fig. 'I shows an alternative arrangement in which the cup I6 with its 'mandrel I9 is secured to a box cover 34. The side of the box 35 over which the cover fits, is providedwith a spring. arm 36 having an end portion 31 turned in for' yalso in the mode by which the mandrel v,Ill is secured to the plate Ill, such changes including the substitution of other resilient means for thespring 22. Likewise, the barb head ofthe mandrel is susceptible to various modifications to accommodate it to different modes of fabrication.

While I have described my invention in detail in its present preferred embodiment, it will be obvious to those skilled in thevart,V after understanding my invention, that various changes and modifications may be made therein without departing from the spirit or scope thereof. I`aim` nermost ends thereof being bent toward thev opening axis and to a position substantially parallel with the plate;4 an outer plate overlying the inner plate having aninwardly projecting open end cup passing through the inner plate opening, a mandrel passing through and axially movable and rotatable relative to the cup, provided with turning and pressing means at its .outer end and provided with an enlarged tapered inner head end adapted, when pressed inwardly, to pass between the prong ends, said mandrel head at a short distance from the inner mandrel end having opposed notches formed therein, the notch surfaces adjacent the inner mandrel end being plane and substantially parallel to the inner plate and the notch surfaces toward the outer mandrel end being sloped, said notches being engageable by the prong inner ends to prevent withdrawal of the mandrel therefrom, and a spring embracing the mandrel disposed within said cup, one spring end bearing on the cup inner end and the other spring end bearing on the outer mandrel end, said enlarged inner end of the mandrel being engageable with the inner cup end to prevent withdrawal of the mandrel through the cup.

2. In a fastening assembly, an outer plate having an open-end cup therein, a mandrel having enlarged ends and a shank of smaller diameter,

the shank passing through said cup but the enlarged ends being larger than the cup opening, a spring embracing the shank bearing at one end on the cup and at its other end on the outer enlarged end, tending to urge the inner enlarged end toward the plate, said inner enlarged end being tapered and having opposed notches therein comprising surfaces facing and substantially parallel to said plate, an inner plate having an opening through which said mandrel and cup passes, and oblique spring prongs secured to the inner plate on opposite sides of the opening, the inner ends of said prongs being bent toward the opening axis and lying substantially parallel to said plates, said prong inner ends being separable by passage of the tapered mandrel end therebetween and being engageable with said notches upon inward pressing of the mandrel against the action of said spring, said prong ends being separable from the mandrel notches by mandrel rotation.

CHARLES E. HATHORN. 

